Grinding machine



Oct. 24, 1933- H. G. wElNLAND GRINDING MACHINE Filed Aug. l2, 1929 INVENTOR ATTORNEYS Patented Oct. 24, 1933 UNITED STATES PAT-ENT OFFICE GRINDING MACHINE Ohio Application August 12, 1929. Serial No. 385,349

6 Claims.

This invention relates to grinding machines, it more particularly relating to a machine of this kind which has a grinding wheel and motor for operating the wheel, together with driving devices between the motor and wheel adapted to be altered whereby the speed of the wheel may be altered as the wheel wears to maintain a peripheral speed within certain limits.

The object of my invention is to provide means whereby an alteration of the driving devices, so proportioned to the diameter of the grinding wheel as to prevent an unsafe peripheral speed of the wheel may be insured.

A more specific object of the invention is to provide means whereby the insertion of a fresh grinding wheel of a given diameter is prevented where the alteration of the driving devices is unsuitable to furnish a correct peripheral speed to the wheel.

A further object of the invention isA to provide means for preventing an alteration of the driving devices to increase the speed of the grinding wheel as the wheel wears until the wheel has been reduced to a given diameter.

Other objects of the invention will appear from the accompanying description and claims.

In the accompanying drawing:

Fig. 1 is a top plan view of a grinding machine having my improvements.

Fig. 2 is a side elevation of the same.

Fig. 3 is an enlarged section on the line 3-3 of Fig. 1.

Fig. 4 is an enlarged section on the line 4-4 of Fig. 2.

My invention is shown applied to a grinding machine of the portable type, although not necessarily limited to that particular type of machine. Referring to the drawing, 1 represents a tubular support which has connected therewith 40 a hanger 2 which is hung from the hook of a freely movable rod 3 suspended from any suitable point so that the machine may be readily swung from one position of operation to another. The grinding wheel 4 is mounted at the forward 45 end of the tubular support in the usual way, there being provided a head 5 which surrounds the upper portion of the wheel and provided with suitable bearings for the shaft 6 upon which the wheel is mounted.

The rear end of the tubular support has a bifurcated head 7, the two arms of which carry a rod 8 upon which is pivotally hung a frame 9 which supports an electric motor 10. The shaft 11 of the motor projects beyond the frame 7 and Y has provision for removably connecting therewith a pulley 12 of any suitable size over which passes a belt 13, the belt also passing about another pulley 14 on the shaft 6 of the grinding` wheel.

In order to secure the correct peripheral speed for the grinding wheel 4, pulleys of different sizes are connected with the shaft of the motor and for that purpose the motor frame is swung forwardly or rearwardly to secure the proper tightness of the belt. To hold'the motor frame in its proper position of adjustment the frame has pivotally connected therewith an eye-bolt 15 which is inserted through a loose sleeve 16 pivotally connected with the head 7. The eye of the bolt 15 is threaded on a rod 17 carried by a pair of arms 18 (one only of which is shown) which prof 70 ject from the motorv frame, while the sleeve 16 has a pair of trunnions 19 journaled in ears 20 projecting from the head 7, but one trunnion and ear being shown in the present case..

In order toi insure the correct peripheral speed of the grinding wheel 4, I have provided a gage or stop which will not only prevent the insertion of a new wheel until after the change of speed devices have been adjusted to suit them tothe diameter of the new wheel, but which will also prevent the driving devices from being altered to increase the speed of the grinding wheel until the grinding wheel has been reduced to a given diameter. Connected with the motor frame is a rod 20. As shown best in Fig. 4, the member 9 85 of the motor'frame has an arm 21 to which is pivotally connected one end of a link 22, the other end of the link being pivoted to a sleeve 23 which is adjustably secured to the rear end of the rod 20 by a set-screw 24. The forward end of the 90 rod 20 is pivotally connected with the bent lever 25, the rod being suitably bent to correctly position it with respect to the lever. One end of the lever is pivotally connected with upstanding ears 26 on the head 5 and the other end of the lever 95 has pivotally connected therewith a pin 27 which extends loosely through an aperture in the head 5 in line with the grinding wheel.

The operation is as follows: After the grinding wheel has worn to a given degree, the change of speed is effected by substituting a pulley of larger diameter upon the motor shaft so as to increase the speed of the grinding wheel to thereby increase the peripheral speed of the wheel to the desired degree. In order to effect this change of speed it is necessary to swing the motor frame forwardly to decrease the distance between the centers of the motor shaft and the grinding wheel shaft. When this is done the pin 27 will be projected toward the periphery of the grinding wheel.`

If the diameter of the grinding wheel has not been reduced sufciently to require a change ci speed, the nger 27 will contact the periphery of the wheel, making it impossible to bring the centers of the two shafts close enough together to allow the pulleys to receive the belt. In the event, however, that the grinding wheel has been reduced to such a diameter as to require a change of speed, such a change is made and the pin 27 remains in its projected position and becomes a bar to the insertion of a fresh grinding wheel of larger diameter, thereby making it necessary to place a pulley of smaller diameter upon the motor shaft suitable to impart a proper peripheral speed to the fresh grinding wheel; such change requiring the motor frame to be swung away from the grinding wheel and the consequent withdrawal of the pin.

Having thus described my invention, I claim:

1.,In a machine of the character described, a grinding wheel, a motor, driving devices between said motor and wheel comprising pulleys and a belt, one of said pulleys being removable, said motor being bodily movable to and from the grinding wheel to compensate for diierent `sized pulleys to eiect changes of speed, and stop means extending from the motor and cooperating with the periphery of the wheel so as to be regulated by the size of the wheel to control such movement of the motor.

2. In a machine of the character described, an insertable grinding wheel, a motor, driving devices between said motor and wheel including a pair of pulleys and a belt, one oi said pulleys being removable, said motor being bodily movable to and from said wheel to permit the use of different size pulleys to effect a change of speed, and stop means movable with the motor` Y, to prevent the insertion of a grinding wheel of grinding wheel, a motor, driving devices between said motor and wheel having a removable driving element, said motor being bodily movable to and from the grinding Wheel to compensate for different sized driving elements to eectl changes of speed, and a gauge member cooperating with said wheel movable with the motor to control such movement of the motor.

4,. In a machine of the character described, a grinding wheel, a motor, driving devices between motor and wheel comprising a removable driving element, said motor being bodily movable to and from the grinding wheel to compensate for diilerent sized driving elements to effect changes of speed, a rod pivotally connected with the frame of the motor, a pivoted lever to which the other end of the rod is pivotally connected, and a pin pivotally connected with said lever and cooperating with the periphery of the grinding wheel to control such movement of the motor.

5. In a machine of the character described, an insertable grinding wheel, a mounting therefor, a motor, driving devices between said motor and wheel comprising a removable driving element, said motor being bodily movable to and from said wheel to permit the use of diflerent sized driving elements to effect a change of speed, and a stop member cooperating with the wheel movable with the motor arranged to prevent the insertion of a driving element of given size until the desired change has been made in the size of the driving elements.

6. In a machine of the character described, an

insertable grinding wheel, a motor, driving devices between said motor and wheel comprising a removable driving element, means movable with the motor to prevent the insertion of a grinding wheel of given diameter until said removable driving element has been substituted with a driving element to impart a proper pe-f 

